A method of, and a system for, controlling a drilling operation

ABSTRACT

A system ( 10 ) for controlling a drilling operation by a drill rig ( 12 ) includes a receiver ( 16 ) for receiving sensed data related to the drilling operation. A processor ( 18 ) is in communication with the receiver ( 16 ), the processor ( 18 ) processing the sensed data to estimate at least one geological property of interest of a zone ( 20 ) in which the drill rig ( 12 ) is active. The processor ( 18 ) is configured to operate as a decision engine ( 22 ) to optimise the drilling operation automatically by changing at least one drilling related parameter during the drilling operation based on the at least one geological property of interest.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Australian ProvisionalPatent Application No 2013901627 filed on 8 May 2013, the contents ofwhich are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates, generally, to controlling a drill rig and, moreparticularly, to a method of, and a system for, controlling a drillingoperation. The disclosure has particular, but not necessarily exclusive,application in controlling a drill rig for drilling blast holes on abench in an open cut mine. It will, however, be appreciated that thedisclosure could apply to the drilling of exploration holes or to thedrilling of an array of holes in a mine face in underground mines.

BACKGROUND

At present, automated drill rigs are used whether for autonomouslydrilling blast holes in a drill bench of an open cut mine or in a mineface of underground mines. However, operator oversight is required tomonitor the state of drilling of the drill rig to ensure that themeasurement while drilling (MWD) data remains within specification.Reasons for the MWD data falling outside specification include a worndrill bit, an incorrect drill bit for the geological conditions or anincorrect drill bit for the required mode of drilling for the geologicalconditions.

Should the operator determine that the MWD data is outsidespecification, the operator needs to determine if it is preferable tochange the drill bit to provide improved efficiency or to continue withthe drilling operation with the current drill bit albeit with the MWDdata outside specification. The reason for this is that changing a drillbit is a relatively time consuming process and any benefit that may begained from changing the drill bit may be outweighed by the time takento do so.

SUMMARY

In one aspect, there is provided a method of controlling a drillingoperation by a drill rig, the method including

sensing data related to the drilling operation;

processing the sensed data to estimate at least one geological propertyof interest of a zone in which the drill rig is active; and

based on the at least one geological property of interest, automaticallyoptimising the drilling operation by changing at least one drillingrelated parameter during the drilling operation.

In this specification, the term “drilling related parameter” is to beunderstood, unless the context clearly indicates otherwise, as being aparameter other than those mechanical drill data of the drill rig thatprovide the sensed data and the “drilling related parameters” includesat least one of a drill bit of a drill string of the drill rig and adrill model for the area to be drilled by the drill rig. Further, theterm “automatically” is to be understood, unless the context clearlyindicates otherwise, as being a system decision rather than an operatordecision.

The method may include selecting the data sensed from the groupconsisting of: mechanical drill data (such as rotation speed, rotationdirection, pull down speed, pull down pressure, pull up speed, depthsensor, air pressure, water fluid flow rate, navigation position,rotation pressure, bit pressure, or the like), geophysical data,geochemical data, and any combination of the foregoing.

The method may include providing the sensed data, via a communicationslink, to a processor for processing the sensed data to estimate the atleast one geological property of interest, the at least one geologicalproperty of interest including strata boundaries and metrics related tosubstrate hardness. The processor may be mounted on the drill rig or,instead, the processor may be located remotely.

The method may include optimising the drilling operation in respect ofat least one specified criterion. The method may include selecting theat least one specified criterion from the group consisting of:maximising rate of penetration of the drill bit or minimising time takento drill a hole, maximising bit life, maximising the rate of drillingthe zone by changing an order in which holes of a drill pattern for thezone are to be drilled, and any of combination of the foregoing.

The method may include optimising the drilling operation by modifyingthe operation of the drill rig directly based on the data sensed. Inaddition, or instead, the method may include optimising the drillingoperation by updating a model of the drilling operation based on thedata sensed and controlling the drill rig using the updated model.

Where the at least one drilling related parameter to be changed includeschanging the drill bit of the drill rig, the method may includefactoring in the time taken to change the drill bit in determiningwhether or not such an action optimises the drilling operation.

The method may include changing the drill bit in dependence on a mode ofdrilling of the drill rig, for example, rotary or percussive drilling,selected to optimise the drilling operation.

In a second aspect, there is provided a system for controlling adrilling operation by a drill rig, the system including

a receiver for receiving sensed data related to the drilling operation;

a processor in communication with the receiver, the processor processingthe sensed data to estimate at least one geological property of interestof a zone in which the drill rig is active; and

wherein the processor is configured to operate as a decision engine tooptimise the drilling operation automatically by changing at least onedrilling related parameter during the drilling operation based on the atleast one geological property of interest.

The sensed data may be selected from the group consisting of: mechanicaldrill data, geophysical data, geochemical data, and any combination ofthe foregoing.

The system may include a communications link for providing the senseddata from the receiver to the processor.

The at least one geological property of interest may include strataboundaries and metrics related to substrate hardness.

The processor, operating as the decision engine, may be configured tooptimise the drilling operation for at least one specified criterion.The at least one specified criterion may be selected from the groupconsisting of: maximising rate of penetration of the drill bit orminimising time taken to drill a drill hole, maximising bit life,maximising the rate of drilling the zone by changing an order in whichholes of a drill pattern for the zone are to be drilled, and any ofcombination of the foregoing.

The processor may be configured, where the at least one drilling relatedparameter to be changed includes changing the drill bit of the drillrig, to factor in the time taken to change the drill bit in determiningwhether or not such an action optimises the drilling operation.

The disclosure extends to software that, when installed on a computer,causes the computer to perform the method as described above.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments of the disclosure are now described by way of example withreference to the accompanying drawings in which:

FIG. 1 shows a schematic representation of a drill rig and a system forcontrolling a drilling operation carried out by the drill rig;

FIGS. 2-4 show screenshots of stages in an automated bit changingoperation on a drill rig; and

FIG. 5 shows a flow chart of an embodiment of a method of controlling adrilling operation by a drill rig.

DESCRIPTION OF EMBODIMENTS

In FIG. 1 of the drawings, reference numeral 10 generally designates asystem for controlling a drilling operation by a drill rig 12. Thesystem 10 includes an operating system 14 comprising various modules. Inparticular, the operating system 14 comprises a receiver 16 forreceiving sensed data relating to the drill rig 12 carrying out thedrilling operation. The receiver 16 is in communication with a processor18. The processor 18 is operative to process the sensed data to estimateat least one geological property of interest of a zone, such as a minebench, 20 in which the drilling rig 12 is active.

The operating system 14 further includes a decision engine 22,configured as a part of the processor 18, but shown as a separate modulefor description purposes, to optimise the drilling operation byautomatically changing at least one drilling related parameter duringthe drilling operation based on the geological property, or properties,of interest.

The operating system 14 also includes a geological model of the bench 20to be drilled which is stored in a database 24 and with which theprocessor 18 is in communication.

The modules 16, 18 and 22 of the operating system 14 are implemented insoftware and can either form part of a controller 26 of the drill rig 12or may be arranged remotely from the drill rig 12 communicating with thedrill rig 12 via a communications link 28, typically a wirelesscommunications link.

While the system 10 has been developed particularly for use incontrolling a drill rig 12 operative on a bench 20 of an open cut mineto drill a drill pattern 30 of blast holes 32 in the bench 20, thoseskilled in the art will readily appreciate that the system 10 could beused in other applications as well. Those other applications include,for example, drilling of sample or exploration holes in the bench 20,drilling an array of blast holes in a mine face in an underground mine,or the like. For ease of explanation, the disclosure will be describedwith reference to its application to the drilling of blast holes 32 inthe bench 20.

The drill rig 12 includes a platform 34 which supports a drill mast 36.The drill mast 36 carries a drill string 38, an operatively lower end ofwhich includes a replaceable drill bit 40. The drill mast 36 ispivotally arranged about a pivot point 42 on the platform 34 to pivot tothe position shown, for example, in FIGS. 2-4 of the drawings to enableaccess to be gained to the drill bit 40 for maintenance and/orreplacement purposes. The drill rig 12 further includes an auto bitchanger module 44 carried by the platform 34 of the drill rig 12.

Further, the drill rig 12 includes a sensor pack, indicatedschematically at 46 in the drawings, which provides sensed data relatingto the status of various mechanical drilling parameters known asMeasurement While Drilling (MWD) data and provides the sensed MWD datato the receiver 16. The MWD data include: rotation speed of the drillbit 40, rotation direction of the drill bit 40, pull down speed, pulldown pressure, pull up speed, depth, air pressure, water fluid flowrate, rotation pressure, bit pressure, or the like.

In addition, the drill rig 12 has a position determining sensor 48, suchas a GPS unit, for monitoring and locating the position of the drill rig12 on the bench 20. The position determining sensor 48 is, in anexample, a high precision GPS (HPGPS) unit.

The auto bit changer module 44 is shown schematically in FIG. 1 of thedrawings to be standing proud of the platform 34. However, this has beenillustrated in this way purely for description purposes. In practice,the auto bit changer module 44 is housed within the platform 34 as shownmore clearly in FIGS. 2-4 of the drawings. The auto bit changer module44 includes a cover member 46 (FIGS. 3 and 4) covering a cradle 48. Thecradle 48 comprises a plurality of receptacles 50, in each of which adrill bit 40 is receivable.

In the illustrated embodiment, only two drill bits 40.1 and 40.2 (FIG.4) are shown. It will be appreciated that, if necessary, a greaternumber of drill bits 40 are able to be housed in the cradle 48.

The cradle 48 is pivotally displaceable on the platform 34 to pivot intothe position shown in FIGS. 3 and 4 of the drawings to align one of thereceptacles 50 with the drill string 38 of the drill rig 12 when themast 36 has been pivoted to expose the drill bit 40. In thisorientation, the drill bit 40 at the end of the drill string 38 can bereceived in that receptacle 50 in register with the drill bit 40 at theend of the drill string 38. An upstream end of each receptacle 50 has apair of opposed jaws 52. The jaws 52 engage opposed flats 54, one ofwhich is shown in FIG. 3 of the drawings, to restrain the drill bit 40,when received in its receptacle 50, against rotation. By counterrotation of the drill string 38, the drill bit 40 is disconnected fromthe drill string 38.

The cradle 48 is displaceable laterally relative to the platform in thedirection of arrows 56. Thus, referring to FIG. 4 of the drawings, oncethe drill bit 40.1 has been disconnected from the drill string 38, thecradle 48 is displaced laterally relative to the drill string 38 so thata new drill bit 40.2 to be connected to the drill string 38 is broughtinto alignment with the end of the drill string 38. Rotation of thedrill string 38 relative to the drill bit 40.2 connects the drill bit40.2 to the drill string 38 for subsequent use.

The cradle 48 carries either a plurality of drill bits 40 of the sametype and/or a plurality of different types of drill bits 40. In theformer case, when one drill bit 40 becomes worn, the worn drill bit canbe replaced with a new drill bit to improve drilling efficiency. In thelatter case, the different types of drill bits cater for strata ofdifferent hardness to be drilled in the bench 20 and/or to cater fordifferent drilling modes, such as, for example, rotary drilling versuspercussive drilling. For example, the drill bit 40.1 may be suited forrotary drilling operations with the drill bit 40.2 being used forpercussive drilling operations.

The auto bit changer module 44 is configured to operate automatically(as defined) under control of the controller 26 of the drill rig 12.

The platform 34 is supported on a pair of spaced tracks 58, one of whichis shown in FIG. 1 of the drawings. A jack 60 is arranged at each end ofeach track 58, the jacks 60 depending from the platform 34. In use, thejacks 60 are lowered relative to the platform 34 when a drillingoperation is to be effected to raise the tracks 58 off a surface of thebench 30.

The operating system 14 of the system 10 includes a user interface 62.The user interface 62 comprises a display 64 on which the bench 20 andthe position of the drill rig 12 on the bench 20 is displayed. The userinterface 62 also includes various inputting devices such as a keyboard66, other pointing devices (not shown) and/or touch screen facilities onthe display 64. The user interface 62 receives input from the processor18 of the operating system 14 as well as, if necessary, from an operatorof the operating system 14.

Referring more particularly to FIG. 5 of the drawings, a method ofcontrolling operation of the drill rig 12 is now described in greaterdetail.

As shown at step 68, the sensor pack 46 of the drill rig 12 senses theMWD data which, together with the position information sensed by thesensor 48, are made available to the processor 18 via the receiver 16.In addition, where the drill rig 12 is equipped with suitable sensors(not shown), geophysical data and geochemical data are also sensed bythe sensor pack 46 with the geophysical data and geochemical data beingmade available to the processor 18 via the receiver 16.

Once the processor 18 has received the sensed data from the receiver 16,the processor 18 processes the received data to estimate geologicalproperties of interest as shown at step 70 in FIG. 5 of the drawings.The geological properties of interest include boundaries, moreparticularly, geological boundaries between strata in the substrate ofthe bench 20 and metrics proportional to hardness of the substrate beingdrilled by the drill rig 12.

Based on the processed data and the estimated geological properties ofinterest, the decision engine 22 of the processor 18 then determineswhether or not the drilling operation being carried out by the drill rig12 is able to be optimised by changing at least one drilling relatedparameter during the drilling operation as shown at step 72 in FIG. 5 ofthe drawings. The decision engine 22 considers changing at least one oftwo parameters in determining whether or not the drilling operation isable to be optimised. The first parameter is changing the drill bit 40and whether or not doing so would optimise the drilling operation andthe second parameter which is considered by the decision engine 22 is anorder in which the blast holes 32 of the drill pattern 30 are drilledand, whether or not changing the order of drilling the blast holes,based on the geological properties of interest which have been estimatedby the processor 18, would optimise the drilling operation.

As will be appreciated, it is a time consuming operation to change thedrill bit 40, whether automatically or manually, since the drill string38 must be raised out of the hole being drilled, the mast 36 pivoted tothe position shown in FIGS. 2-4 of the drawings, the auto bit changermodule 44 activated and the drill bit 40 replaced. Hence, as shown atstep 74 in FIG. 5 of the drawings, the decision engine 22 factors intoits decision the time taken to change the drill bit on the drill rig 12in determining whether or not the drilling operation can be optimised.

If a determination is made that a more efficient drilling operation canbe effected by way of changing the drill bit 40, the operating system 14instructs the controller 26 to change the drill bit 40 as shown at step76 in FIG. 5 of the drawings. This is an entirely automatic operationwithout operator intervention.

Once the drill bit 40 has been changed as shown at step 76 or a decisionhas been made by the decision engine 22 to continue with the drillingoperation without replacing the drill bit 40, the drilling operationcontinues as shown at step 78 and, once the entire drill pattern 30 hasbeen drilled in the bench 20, the drilling operation ends as shown atstep 80.

The system 10 optimises drilling by the drill rig 12 to maximise ametric or metrics of interest as described above. In one embodiment, thesystem 10 optimises the drilling operation to maximise a rate ofpenetration of the drill bit 40 through the substrate of the bench 20or, in other words, to minimise the time taken to drill a blast hole 32in the bench 20. This is done by automatically selecting the mostappropriate drill bit 40 for the geological properties of interest ofthe bench 20 as well as the drilling mode which is optimal for thatgeology. As indicated above, the geological properties of interest aredetermined by the MWD data, measured by the sensor pack 46 of the drillrig 12.

The MWD data are used directly in controlling the drill rig 12 via theprocessor 18. Instead, the MWD data are loaded into the model containedin the database 24 and the model is updated with the MWD data to be usedby the processor 18 in controlling operation of the drill rig 12, asindicated at 82 in FIG. 5 of the drawings. As indicated above, one ofthe considerations in determining whether or not to change the drill bit40 is factoring in the time taken automatically to perform any change ofdrill bit.

In another embodiment, the system 10 is operative to optimise thedrilling mode and bit selection based on the MWD data from the sensorpack 46 and/or data in the model in the database 24, optionally suitablyupdated with the MWD data, to maximise drill bit life.

In a further embodiment, the system 10 is configured to optimise thedrilling operation by changing the order in which the holes 32 of thedrill pattern 30 are to be drilled in the bench 20 and burden based onthe MWD data from the sensor pack 46 or the model contained in thedatabase 24, optionally suitably updated with the MWD data from thesensor pack 46. This is shown at step 84 in FIG. 5 of the drawings. Asan example, the processor 18 may determine that, as a result of theupdated model, it would be more efficient to drill all holes in softerstrata rather than harder strata first, or vice versa, rather thanalternating between hard and soft strata with the associated requiredbit changes. Conversely, the processor 18 may determine that the timetaken to change bits may be less than the time taken to tramsequentially to all hole locations in harder or softer strata, as thecase may be, and may alter the drilling operation accordingly.

If the processor 18 determines that the hole order should be alteredthis is done by reprogramming a tramming program of the drill rig 12 asshown at step 86 following which the drilling operation continues aspreviously described and as shown at step 78.

In still a further embodiment, the system 10 is configured to optimisethe drilling operation carried out by the drill rig 12 by a combinationof changes, i.e., changing drill bit, drill mode and hole order tooptimise drilling of the bench 20.

At present, a hole pattern 30 is drilled in the bench 20 using anautomated drill rig with or without an auto bit changing module.However, an operator is still required to determine whether or not adrill bit should be changed in order to optimise the drilling operationbased on MWD data received. Thus, operator intervention is stillrequired. However, with the provision of the system 10, the need foroperator intervention is obviated and the decision to change at leastone drilling related parameter such as changing a drill bit and/or holeorder of the pattern, is effected automatically resulting in improveddrilling efficiencies and optimisation of the drilling operation.

It will also be appreciated that updating the model with the MWD dataresults in a more accurate geological model which has benefits in thesubsequent charging of the blast holes with the required recipe ofexplosives. In other words, it enables the desired blast pattern to beachieved to be assessed more accurately and given effect to.

It will be appreciated by persons skilled in the art that numerousvariations and/or modifications may be made to the above-describedembodiments, without departing from the broad general scope of thepresent disclosure. The present embodiments are, therefore, to beconsidered in all respects as illustrative and not restrictive.

1. A method of controlling a drilling operation by a drill rig, themethod including: sensing data related to the drilling operation;processing the sensed data to estimate at least one geological propertyof interest of a zone in which the drill rig is active; and based on theat least one geological property of interest, automatically optimisingthe drilling operation by changing at least one drilling relatedparameter during the drilling operation.
 2. The method of claim 1 whichincludes selecting the data sensed from the group consisting of:mechanical drill data, geophysical data, geochemical data, and anycombination of the foregoing.
 3. The method of claim 1 which includesproviding the sensed data, via a communications link, to a processor forprocessing the sensed data to estimate the at least one geologicalproperty of interest, the at least one geological property of interestincluding boundaries and metrics related to substrate hardness.
 4. Themethod of claim 1 which includes optimising the drilling operation inrespect of at least one specified criterion.
 5. The method of claim 4which includes selecting the at least one specified criterion from thegroup consisting of: maximising rate of penetration of the drill bit orminimising time taken to drill a hole, maximising bit life, maximisingthe rate of drilling the zone by changing an order in which holes of adrill pattern for the zone are to be drilled, and any of combination ofthe foregoing.
 6. The method of claim 1 which includes optimising thedrilling operation by modifying the operation of the drill rig directlybased on the data sensed.
 7. The method of claim 1 which includesoptimising the drilling operation by updating a model of the drillingoperation based on the data sensed and controlling the drill rig usingthe updated model.
 8. The method of claim 1 in which, where the at leastone drilling related parameter to be changed includes changing the drillbit of the drill rig, the method includes factoring in the time taken tochange the drill bit in determining whether or not such an actionoptimises the drilling operation.
 9. The method of claim 8 whichincludes changing the drill bit in dependence on a mode of drilling ofthe drill rig selected to optimise the drilling operation.
 10. A systemfor controlling a drilling operation by a drill rig, the systemincluding: a receiver for receiving sensed data related to the drillingoperation; a processor in communication with the receiver, the processorprocessing the sensed data to estimate at least one geological propertyof interest of a zone in which the drill rig is active; and wherein theprocessor is configured to operate as a decision engine to optimise thedrilling operation automatically by changing at least one drillingrelated parameter during the drilling operation based on the at leastone geological property of interest.
 11. The system of claim 10 in whichthe sensed data is selected from the group consisting of: mechanicaldrill data, geophysical data, geochemical data, and any combination ofthe foregoing.
 12. The system of claim 10 which includes acommunications link for providing the sensed data from the receiver tothe processor.
 13. The system of claim 10 in which the at least onegeological property of interest includes strata boundaries and metricsrelated to substrate hardness.
 14. The system of claim 10 in which theprocessor, operating as the decision engine, is configured to optimisethe drilling operation for at least one specified criterion.
 15. Thesystem of claim 14 in which the at least one specified criterion isselected from the group consisting of: maximising rate of penetration ofthe drill bit or minimising time taken to drill a hole, maximising bitlife, maximising the rate of drilling the zone by changing an order inwhich holes of a drill pattern for the zone are to be drilled, and anyof combination of the foregoing.
 16. The system of claim 10 in which theprocessor is configured, where the at least one drilling relatedparameter to be changed includes changing the drill bit of the drillrig, to factor in the time taken to change the drill bit in determiningwhether or not such an action optimises the drilling operation. 17.Software that, when installed on a computer, causes the computer toperform the method of claim 10.